Nitrous in a stock 2000 GT

[Chris2000GTvert]

MY car is just about stock, and I really don't use my power in the car much at all. What the car provides stock is fine (I have just an air intake, nothing else). The only thing I do kinda like to have though, is the ability, if the need comes (like someone challenges to a race) to move the car a bit faster.

I was originally thinking about modding engine parts to get faster, like doing exhaust (any recs?) catback, and bassani x pipe, or doing gears (I dont want this though cause I normally drive like an old woman)...

I also thought about supercharging, but as I'm trying to get across, I don't drive fast normally, so I don't think always on power is too good for me.

So the thought of Nitrous in small dosage came to mind, but I dont know much about its safety in the car. The kit I'm looking at is made by NOS and is recommended by the guys at the speed shop around the corner. They are selling the base kit for 820$ (adjustable from 75 to 150 hp shots) and warmer for 140 and 140 for purge valve. I'm probably gunna get it installed nicely somewhere (Im expecting to pay 350$?) and buy the extras as recommended by earlier threads on here. I'm then thinking of just keepiong it hooked up to run 75, and only using it maybe on a weekly occurence. Do you guys agree with this or do you think I should do the exhaust...gears...etc upgrades first?

Also, as far as the purge valve, is it needed...and should I get it?

Thanks so much guys...

-Chris